code: def test_merge_known_to_known(
      df_left, df_right, ddf_left, ddf_right, on, how, shuffle_method
  ):
      # Compute expected
      expected = df_left.merge(df_right, on=on, how=how)
  
      # Perform merge
      result = ddf_left.merge(
          ddf_right, on=on, how=how, shuffle_method=shuffle_method
      )
  
      # Assertions
      assert_eq(result, expected)
      assert_eq(result.divisions, tuple(range(12)))
      assert len(result.__dask_graph__()) < 80
  
imports: from __future__ import annotations
  import numpy
  import pandas
  import pytest
  import dask.dataframe
  from dask.dataframe._compat import PANDAS_GE_210
  from dask.dataframe.utils import assert_eq
label_desc: Use image node_id 13 for calling a global function with example usage: test_merge_known_to_known(df_left, df_right, ddf_left, ddf_right, on, how, shuffle_method) without return types